1. Field of the Invention
The present invention relates to a method and apparatus for embedding data into video images, and more particularly to a method and apparatus for inserting receiver identification codes into video images received from a television broadcasting station.
2. Description of the Related Art
Watermarking is a process by which electronically transmitted images are encoded with identification data so that the images can later be traced back to their originator. The encoded identification data is referred to as a “watermark”. The identification data may include the originator's name, a company name, an address, or any other information that provides a unique identification. Typically, the identification data are embedded into an image by manipulating color information of the image. The identification data is embedded in the images in such a way as to be undetectable to the casual observer. In other words, the image appears the same as it would with no watermark embedded therein.
Some watermarking techniques have been used in the context of the World Wide Web. By using watermarked images, World Wide Web content providers can more easily determine if someone has borrowed their images and used them in another context. Similarly, there have been discussions about networks like HBO doing watermarking on a network layer or broadcaster layer such that DIRECTV, for instance, would have one watermark, TCI Cable would have a different watermark, DISH NETWORK would have a third watermark, etc. However, such techniques do not provide for watermarking on a receiver-by-receiver basis. Thus, one would be able to determine that a particular signal originated from a DIRECTV/HBO feed, for example, but would not be able to trace the signal to a particular receiver.